The Development of Novel Textures in Rare Earth Element Containing Magnesium Alloys

Abstract:

Magnesium (Mg) is a hexagonal close-packed light metal whose deformation re-sponse is characterized predominantly by easy slip on the f0002g basal plane at temperaturesbelow 200°C. Rolled sheet products develop a strong basal texture and become \plasticallychallenged" in subsequent forming operations. In the literature, additions of rare earth ele-ments (REE) to Mg have inconsistently reported non-basal texture formation. In this work,Mg-0.2wt%Gd and 0.2-wt%La were investigated to determine whether the presence of theseelements contributed to non-basal texture formation after elevated temperature plane straincompression. Test specimens were prepared from book-mould castings after homogenization at400°C, and reduced 50% in a channel die at 250, 325, or 375°C and 10^-2/s. The stress-strainbehaviours were all characterized by apparent twin-related softening, followed by monotonichardening to the end of the imposed deformation. The yield stress for Mg-0.2%La (15-22 MPa)was higher and less temperature dependent than for Mg-0.2%Gd (10-18 MPa). Texture mea-surements indicate the spread of ideal basal texture about TD with increased temperature, butalso also greater non-basal textures in the Mg-0.2%Gd alloy, particularly at 325°C. Electronchanneling contrast imaging revealed a more re ned and homogeneous substructure in the Gd-containing alloy compared with larger microbands in the La-containing alloy, and suggests thatcontinuous recovery and other available slip systems may contribute to these di erences.

• Periodical: Advanced Materials Research (Volume 409)
• Pages: 343-349
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.409.343
• Online since: November 2011
• Authors: M. Majkut, Bradley J. Diak, L.W.F. Mackenzie
• Keywords: Gadolinium, Lanthanum, Magnesium, Plane Strain Compression, Rare Earth (RE), Texture

References

This article has no references.